After Lorenzo Cain hammered a two-run home run in the fourth inning Tuesday to put the Royals ahead of the Rockies 4-1, something felt different.

The Rockies remain the best offense in baseball. They almost routinely score eight or more runs in a game. Their run differential entering Tuesday (plus-55) was the second-best in baseball behind only Oakland. So a three-run deficit is not like a mountain to climb for Colorado.

But this felt different. It felt like the game was over at the halfway point. And it was.[1]

Franklin Morales throws down the rosin bag after giving up a two-run home run in the fourth inning at Kansas City. (Orlin Wagner, The Associated Press)

The Rockies struggled to five hits and one run against Royals ace James Shields. Colorado finished the game with a season-high 12 strikeouts.

Shields met the Rockies with 18 first-pitch strikes. It was his key in attacking Troy Tulowitzki and the Rockies’ active offense. Once he got up, he got out of at-bats with a major-league changeup.

“He threw a lot of changeups. The changeup is pretty much his go-to pitch,” Rockies manager Walt Weiss said of Shields, who earned his 1,500th career strike out in the game, joining Arizona’s Bronson Arroyo, who did the same thing earlier in the night.

“It looked like he was throwing the fastball on the outer part of the plate, on the corner, then he’d go to the changeup. It’s been a good formula for him for awhile.”

Rockies pitcher Franklin Morales, meanwhile, struggled to throw strikes. He now has allowed at least four runs in three straight starts.